公开(公告)号：US20220244118A1

公开(公告)日：2022-08-04

申请号：US17562469

申请日：2021-12-27

Applicant: Hitachi Metals, Ltd. ,  NSK Ltd.

Inventor： Teruyuki NAKAMURA ,  Yuta SUGIYAMA ,  Yiming JIN ,  Kota FUKUDA

IPC: G01L3/10

Abstract: A magnetostrictive torque sensor includes detection coils formed around a magnetostrictive material made of chrome steel or chrome molybdenum steel, a magnetic ring configured to cover around the detection coils, and a drive unit for providing alternating current excitation to the detection coils at an excitation frequency of 50 kHz or more and 333 kHz or less. A torque applied to the magnetostrictive material is detected based on a change in inductance of the detection coils. The magnetic ring is configured by wrapping around the detection coils with an amorphous tape made of amorphous soft magnetic material in a tape shape. The thickness of the magnetic ring is 1.455 times or more as thick as a skin effect thickness of the magnetostrictive material and less than 1.000 mm.

公开(公告)号：US20220074010A1

公开(公告)日：2022-03-10

申请号：US17416756

申请日：2019-12-11

Applicant: NSK LTD.

Inventor： Kota FUKUDA ,  Junji ONO ,  Teruyuki NAKAMURA ,  Yuta SUGIYAMA

IPC: C21D9/28 ,  G01L3/10 ,  B24C1/10 ,  B24C11/00 ,  C21D7/06

Abstract: A method for manufacturing a magnetostrictive torque sensor shaft (100) to which a sensor portion (2) of a magnetostrictive torque sensor (1) is to be attached includes: a heat treatment step of subjecting an iron-based shaft member to a carburizing, quenching, and tempering process; a shot peening step of performing shot peening using a steel shot media having a Vickers hardness at least equal to 1100 and at most equal to 1300, at least in a position on the shaft member, after the heat treatment step, to which the sensor portion (2) is to be attached; and a surface polishing step of subjecting the shaft member after the shot peening to surface polishing.

公开(公告)号：US20220026294A1

公开(公告)日：2022-01-27

申请号：US17416850

申请日：2019-12-11

Applicant: NSK LTD.

Inventor： Kota FUKUDA ,  Junji ONO ,  Teruyuki NAKAMURA ,  Yuta SUGIYAMA

IPC: G01L3/10 ,  B24C1/10 ,  C21D9/00 ,  C21D8/06

Abstract: A method of manufacturing a magnetostrictive torque sensor shaft (100) to which a sensor portion (2) of a magnetostrictive torque sensor (1) is mounted. The method includes heat treatment step of subjecting an iron-based shaft member to a carburizing, quenching, and tempering process, and a shot peening step of performing shot peening using a steel shot media having a Vickers hardness at least equal to 1100 and at most equal to 1300 and being free of boron, at least in a position on the shaft member, after the heat treatment step, to which the sensor portion is to be attached.

公开(公告)号：US20210278296A1

公开(公告)日：2021-09-09

申请号：US17190138

申请日：2021-03-02

Applicant: Hitachi Metals, Ltd. ,  NSK Ltd.

Inventor： Yuta SUGIYAMA ,  Teruyuki NAKAMURA ,  Junji ONO ,  Kota FUKUDA

IPC: G01L3/10

Abstract: A detection circuit for a magnetostrictive torque sensor is configured to detect a torque applied to a magnetostrictive material treated by shot peening. The detection circuit includes a detection coil provided around the magnetostrictive material, and a drive unit for providing alternating current excitation to the detection coil. The torque applied to the magnetostrictive material is detected based on a change in inductance of the detection coil, and the drive unit provides alternating current excitation at a frequency at which a skin effect thickness is not more than an effective depth of the shot peening.